Abdominal aortic aneurysm disease is a common and lethal health problem of older Americans. Substantial[unreadable] evidence links sedentary existence and resulting pro-inflammatory aortic conditions to the pathogenesis of[unreadable] AAA disease. Insights derived from investigations in animal models and high risk patient groups and care of[unreadable] AAA patients have help define our LONG TERM OBJECTIVE; to identify, validate and apply effective nonsurgical[unreadable] therapies to the treatment of AAA disease. The purpose of this proposal is to test the ability of lower[unreadable] extremity exercise to reduce AAA risk, limit small aneurysm progression and modify biologic markers of[unreadable] disease.[unreadable] We have two SPECIFIC AIMS:[unreadable] First, we will perform a cross-sectional correlation study to determine whether lifetime physical activity and[unreadable] measured exercise capacity represent independent risk factors for AAA disease. These studies will test our[unreadable] hypothesis that aortic diameter and activity level will be independently and inversely related; that is, abdominal[unreadable] aorta size adjusted for age, will be increased in A) inidividuals completing questionnaires indicating persistently[unreadable] low levels of physical activity or B) have reduced exercise capacity as defined by clinical testing. Second, we[unreadable] will perform a prospective, randomized controlled longitudinal trial of exercise to suppress small AAA[unreadable] progression. The impact of training will be monitored by both serial surveillance ultrasound imaging and[unreadable] surrogage biologic markers and imaging of disease progression. This will test our hypothesis that supervised[unreadable] exercise training will reduce AAA expansion rates and/or diminish surrogate markers of disease progression.[unreadable] To ACHIEVE THESE AIMS we will apply analyze life time physical activity to several hundred patients with the[unreadable] new diagnosis of small AAA disease, measure aortic diameter in a large cohort of patients with previously[unreadable] defined exercise capacity, and apply supervised exercise training to an additional cohort of small aneurysm[unreadable] patients.[unreadable] This application is RELEVANT to public health in that we will test a new and low risk method of preventing the[unreadable] development or progression of AAA disease, a potentially life threatening condition. In addition, we will develop[unreadable] a framework to test, measure and compare the effectiveness of future novel therapies.